JP2614810B2 - Method for producing single-phase magnetite powder - Google Patents
Method for producing single-phase magnetite powderInfo
- Publication number
- JP2614810B2 JP2614810B2 JP14147393A JP14147393A JP2614810B2 JP 2614810 B2 JP2614810 B2 JP 2614810B2 JP 14147393 A JP14147393 A JP 14147393A JP 14147393 A JP14147393 A JP 14147393A JP 2614810 B2 JP2614810 B2 JP 2614810B2
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- powder
- hematite
- phase
- magnetite powder
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Description
【０００１】[0001]
【産業上の利用分野】本発明は、ヘマタイト粉に有機物
等を加えて不活性ガス中で加熱処理することにより単相
マグネタイト粉を製造する方法に関するものである。製
造した単相マグネタイト粉は、特に限定されるものでは
ないが、例えば磁性流体、電気抵抗素子、電子写真用の
トナーやキャリアなどに広く利用できる材料である。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a single-phase magnetite powder by adding an organic substance or the like to hematite powder and subjecting it to heat treatment in an inert gas. The manufactured single-phase magnetite powder is not particularly limited, but is a material that can be widely used for, for example, magnetic fluids, electric resistance elements, toners and carriers for electrophotography, and the like.
【０００２】[0002]
【従来の技術】従来、マグネタイト粉を製造するには、
一般に以下の３つの方法が知られている。 湿式法：Ｆｅ2+＋２Ｆｅ3+の水溶液をアルカリ性に
し、共沈させる方法。 乾式法：ヘマタイトを水素・一酸化炭素又は水蒸気中
で加熱・還元する方法。 粉砕法：天然に産する磁鉄鉱を粉砕する方法。2. Description of the Related Art Conventionally, to produce magnetite powder,
Generally, the following three methods are known. Wet method: A method in which an aqueous solution of Fe 2+ + 2Fe 3+ is made alkaline and coprecipitated. Dry method: A method of heating and reducing hematite in hydrogen, carbon monoxide or steam. Grinding method: A method of grinding naturally occurring magnetite.
【０００３】[0003]
【発明が解決しようとする課題】しかし、上記のような
従来の方法は、それぞれ次のような欠点がある。 湿式法：共沈により容易に比較的純度の高い微粒子が
得られるものの、製造コストが高く量産には適さない。 乾式法：高圧力水蒸気または水素・一酸化炭素等の比
較的強力な還元性雰囲気下で反応させるため、量産には
危険を伴い、且つ設備が大掛かりとなる。 粉砕法：天然鉱物を出発原料に用いるため、長期間に
わたって安定して高品質の粉体を生産することが難し
い。However, the conventional methods as described above have the following disadvantages. Wet method: Although relatively pure particles can be easily obtained by coprecipitation, the production cost is high and it is not suitable for mass production. Dry method: Since the reaction is carried out in a relatively strong reducing atmosphere such as high-pressure steam or hydrogen / carbon monoxide, mass production involves danger and requires large-scale equipment. Grinding method: Since a natural mineral is used as a starting material, it is difficult to stably produce high-quality powder over a long period of time.
【０００４】本発明の目的は、上記のような従来法に比
較して簡便な設備、単純な工程で、高品質の単相マグネ
タイト粉を大量に且つ安価に安全に製造できる方法を提
供することである。An object of the present invention is to provide a method capable of safely producing a large amount of high-quality single-phase magnetite powder in a large amount at low cost with simple equipment and simple steps as compared with the above-mentioned conventional methods. It is.
【０００５】[0005]
【課題を解決するための手段】本発明は、ヘマタイト粉
に、炭素原子同士の単結合又は二重結合を有する液状
（液体又は溶液）又は粉末状物質を、０．１〜４．０重
量％加え、ほぼ均一に混合した後、不活性ガス中で１２
００〜１４５０℃で加熱処理する単相マグネタイト粉の
製造方法である。ここで、不活性ガス中での加熱処理前
に、造粒処理によりヘマタイト粉を球状顆粒にしておけ
ば、球状のマグネタイト粉を得ることができる。According to the present invention, a liquid (liquid or solution) or a powdery substance having a single bond or a double bond between carbon atoms is added to a hematite powder in an amount of 0.1 to 4.0% by weight. In addition, after mixing almost uniformly, 12 minutes in an inert gas
This is a method for producing a single-phase magnetite powder that is heat-treated at 00 to 1450 ° C. Here, if the hematite powder is converted into spherical granules by a granulation treatment before the heat treatment in an inert gas, a spherical magnetite powder can be obtained.
【０００６】ここでヘマタイト粉に添加する物質は、酸
素を与えて燃焼させることができるような炭素原子同士
の単結合又は二重結合を有する物質であればよい。一般
には例えば、粉末成形などに用いる有機結合剤や分散剤
などの有機物を用いる。球形に造粒する場合には、その
ような有機結合剤を使用するから、その場合には有機結
合剤が造粒工程での結合剤としての作用と加熱処理工程
での還元作用を兼用することができる。その他、アセチ
レンブラックやグラファイトなども使用可能である。そ
の添加範囲を０．１〜４．０重量％とするのは、０．１
重量％未満では添加による還元効果に乏しく、逆に４．
０重量％を超えると、それ以上添加する意味が無いし、
造粒工程が入る場合にはかえって造粒がうまくできず、
更に多くなると生成するマグネタイト粉中に有機物の不
完全燃焼により生成した炭素などの異物が残存し好まし
くないためである。Here, the substance to be added to the hematite powder may be a substance having a single bond or a double bond between carbon atoms which can be burned by giving oxygen. Generally, for example, organic substances such as an organic binder and a dispersant used for powder molding and the like are used. In the case of granulating in a spherical shape, such an organic binder is used. In this case, the organic binder serves both as a binder in the granulation step and a reducing action in the heat treatment step. Can be. In addition, acetylene black, graphite, and the like can be used. The addition range of 0.1 to 4.0% by weight is 0.1% by weight.
If the content is less than 10% by weight, the reducing effect of the addition is poor.
If it exceeds 0% by weight, there is no point in adding it further,
When the granulation process enters, on the contrary, granulation can not be done well,
This is because, when the amount increases further, foreign substances such as carbon generated by incomplete combustion of organic substances remain in the generated magnetite powder, which is not preferable.
【０００７】[0007]
【作用】金属酸化物と有機物とを混合した状態で不活性
ガス雰囲気中で加熱すると、金属酸化物は還元される。
例えば有機物としてプロピレン（ＣＨ3 ＣＨ＝ＣＨ2 ）
を用いた場合、プロピレンが金属酸化物表面では、酸化
物中のＯ-2にＨ+ を奪われてπアリル中間体となる。こ
のような反応は、有機物の種類によらずほぼ同様であ
る。上記のπアリル中間体に酸素が付加されればアクロ
レイン、さもなければ２つのπアリル中間体が二量化し
てベンゼンとなる。この場合、πアリル中間体となるに
は炭素−炭素間の二重結合が必要であるが、金属酸化物
上でＨ+ を奪われることにより炭素−炭素間の単結合が
二重結合に変化するため、最初の状態では炭素−炭素間
の単結合のみでもよい。例えばポリビニルアルコールは
炭素−炭素間の二重結合を持たないが、還元能力は充分
にある。When a mixture of a metal oxide and an organic substance is heated in an inert gas atmosphere, the metal oxide is reduced.
For example, propylene (CH 3 CH = CH 2 ) as an organic substance
When propylene is used, on the surface of the metal oxide, propylene is deprived of H + by O -2 in the oxide to become a π allyl intermediate. Such a reaction is almost the same regardless of the type of the organic substance. If oxygen is added to the above-mentioned π-allyl intermediate, acrolein is produced, otherwise two π-allyl intermediates are dimerized to benzene. In this case, a carbon-carbon double bond is required to become a π allyl intermediate, but a single bond between carbon and carbon is changed to a double bond by depriving H + on the metal oxide. In the initial state, only a single bond between carbon and carbon may be used. For example, polyvinyl alcohol does not have a carbon-carbon double bond, but has a sufficient reducing ability.
【０００８】ヘマタイト（α−Ｆｅ2 Ｏ3 ）を有機物と
混合した状態で不活性ガス中で加熱処理すると、不完全
燃焼状態となり、有機物の熱分解時にヘマタイトから酸
素を奪うことにより該ヘマタイトが還元され、Ｘ線的に
みて単相の（純度ほぼ１００％の）マグネタイト（Ｆｅ
3 Ｏ4 ）に熱転移する。この反応は、極めて効率が良
く、例えば一般のフェライト製造設備を用いて匣鉢に厚
さ数cmにヘマタイト粉を充填して供給しても、それ全体
が良好なマグネタイト粉になる。つまり本発明は有機物
などの不完全燃焼を積極的に利用し、発生したガスを用
いてヘマタイト粉を還元処理しているのである。When hematite (α-Fe 2 O 3 ) is mixed with an organic substance and heat-treated in an inert gas, an incomplete combustion state occurs, and the hematite is decomposed by removing oxygen from the hematite during thermal decomposition of the organic substance. And a single phase (purely 100% pure) magnetite (Fe
3 O 4) To heat transfer. This reaction is extremely efficient. For example, even if hematite powder is filled into a sagger with a thickness of several centimeters and supplied using a general ferrite production facility, the whole becomes a good magnetite powder. That is, the present invention positively utilizes incomplete combustion of organic substances and the like, and reduces hematite powder using the generated gas.
【０００９】因に、有機物等を混入することなく、ヘマ
タイト粉のみを用いて不活性ガス中で加熱処理した場
合、少量のヘマタイト粉を匣鉢の表面に薄く撒いて且つ
長時間にわたって処理すると、一部がマグネタイト粉に
変化することが認められたが、生産効率は極めて低く、
とうてい工業化しうるものではなかった。When heat treatment is carried out in an inert gas using only hematite powder without mixing organic matter or the like, when a small amount of hematite powder is thinly spread on the surface of the sagger and treated for a long time, Although it was recognized that some of them changed to magnetite powder, the production efficiency was extremely low,
It was not something that could be industrialized.
【００１０】[0010]
（実験例Ａ）原料であるヘマタイト粉に、ＰＶＡ（ポリ
ビニルアルコール）０〜３重量％、分散剤としてポリカ
ルボン酸塩１重量％を加え、水と混合してヘマタイト濃
度５０重量％のスラリーとした。そのスラリーをアトラ
イターで１時間攪拌した後、スプレードライヤーで造
粒、顆粒化した。得られた顆粒を窒素雰囲気中で８００
〜１５００℃で２時間加熱処理した。処理後の各相の同
定は粉末Ｘ線回折定性分析により行った。実験結果を表
１に示す。(Experimental example A) To a hematite powder as a raw material, 0 to 3% by weight of PVA (polyvinyl alcohol) and 1% by weight of a polycarboxylate as a dispersant were added and mixed with water to form a slurry having a hematite concentration of 50% by weight. . After the slurry was stirred for 1 hour with an attritor, it was granulated and granulated with a spray drier. The obtained granules are placed in a nitrogen atmosphere for 800
Heat treatment was performed at ℃ 1500 ° C. for 2 hours. Each phase after the treatment was identified by powder X-ray diffraction qualitative analysis. Table 1 shows the experimental results.
【００１１】[0011]
【表１】 [Table 1]
【００１２】上記の実験結果から、次のことが判明し
た。 ＰＶＡを添加せずヘマタイト粉のみの場合（比較例）
は、加熱温度を変えても単相マグネタイトは得られな
い。Ｘ線的に見るとα−Ｆｅ2 Ｏ3 又はＦｅＯの相が存
在する。 ＰＶＡの添加量を２重量％とし、加熱温度を変える
と、１２００〜１４５０℃の範囲では単相マグネタイト
が得られた。しかし１１５０℃以下ではα−Ｆｅ2Ｏ3
が共存し、１５００℃以上ではＦｅＯが共存した。それ
故、加熱温度は１２００〜１４５０℃とする必要があ
る。 加熱温度を１３００℃とし、ＰＶＡの添加量を０．１
〜３．０重量％まで変えた場合は、全て単相マグネタイ
トが得られた。つまり、ＰＶＡの添加は０．１重量％以
上で有効であった。From the above experimental results, the following has been found. When only hematite powder is used without adding PVA (Comparative Example)
Does not provide single-phase magnetite even when the heating temperature is changed. From an X-ray perspective, there is a phase of α-Fe 2 O 3 or FeO. When the addition amount of PVA was set to 2% by weight and the heating temperature was changed, single-phase magnetite was obtained in the range of 1200 to 1450 ° C. However, below 1150 ° C., α-Fe 2 O 3
Coexisted, and at 1500 ° C. or higher, FeO coexisted. Therefore, the heating temperature needs to be 1200-1450 ° C. The heating temperature was 1300 ° C., and the amount of PVA added was 0.1
When the amount was changed to 3.0% by weight, all single-phase magnetite was obtained. That is, the addition of PVA was effective at 0.1% by weight or more.
【００１３】（実験例Ｂ）原料であるヘマタイト粉に、
添加物としてボリビニルアルコール、ポリアクリルアミ
ド、ポリイソブチレン、ポリカルボン酸塩、アルキルナ
フタレンスルホン酸塩（以上は水溶液で添加）、ポリビ
ニルブチラール、ステアリン酸（以上はアルコール溶液
又は分散液で添加）、アセチレンブラック、グラファイ
ト（以上は粉体で添加しアルコールを加えて混合）を各
々２重量％添加し、乳鉢で混合した後、４２５μｍの篩
を通過させて試料とした。篩を通過させたのは、粒子の
大きさを揃えるためである。これらの粒子を６０℃で約
４時間乾燥後、窒素、アルゴン、ヘリウム、空気中にお
いて１２００℃で２時間加熱した。処理後の試料の同定
は粉末Ｘ線回折定性分析にて行った。結果を表２に示
す。(Experimental Example B) Hematite powder as a raw material
As additives, polyvinyl alcohol, polyacrylamide, polyisobutylene, polycarboxylate, alkylnaphthalene sulfonate (the above is added as an aqueous solution), polyvinyl butyral, stearic acid (the above is added as an alcohol solution or dispersion), acetylene black And 2% by weight of graphite (these were added in powder and alcohol was added) and mixed in a mortar, and then passed through a 425 μm sieve to obtain a sample. The reason for passing through the sieve is to make the particle size uniform. After drying these particles at 60 ° C. for about 4 hours, they were heated at 1200 ° C. for 2 hours in nitrogen, argon, helium and air. The sample after the treatment was identified by powder X-ray diffraction qualitative analysis. Table 2 shows the results.
【００１４】[0014]
【表２】 [Table 2]
【００１５】これらの物質は全て同じ傾向を示し、使用
した試料は全て、窒素、アルゴン、ヘリウム中では単相
マグネタイトが得られた。しかし、空気中で加熱処理し
た場合は、全てα−Ｆｅ2 Ｏ3 となった。つまり空気中
のように酸素を多量に含む雰囲気では、単相マグネタイ
トは得られなかった。All of these materials showed the same tendency, and all of the samples used obtained single-phase magnetite in nitrogen, argon and helium. However, when heat treatment was carried out in air, all of them became α-Fe 2 O 3 . That is, single-phase magnetite could not be obtained in an atmosphere containing a large amount of oxygen, such as in air.
【００１６】（実験例Ｃ）次に、加熱温度と保持時間と
の関係について述べる。保持時間が長くなれば有機物を
添加していなくても還元が進んで単相マグネタイト粉が
得られるのではないかという疑問に答えるため、実験を
行った。有機物等を添加していないヘマタイト粉のみに
ついて、窒素雰囲気中、１２００℃で１０時間保持し
た。上記と同様の粉末Ｘ線回折定性分析の結果、α−Ｆ
ｅ2 Ｏ3 相も共存していることが確認された。またＰＶ
Ａを２重量％添加した試料について、窒素雰囲気下、１
１００℃で１０時間保持したところ、同様にα−Ｆｅ2
Ｏ3 相も共存していることが確認された。これらの場合
は、いずれにしても単相マグネタイト粉は得られなかっ
た。(Experimental Example C) Next, the relationship between the heating temperature and the holding time will be described. An experiment was conducted to answer the question that if the retention time was long, reduction would proceed even if no organic matter was added and a single-phase magnetite powder would be obtained. Only the hematite powder to which no organic substance was added was kept at 1200 ° C. for 10 hours in a nitrogen atmosphere. As a result of the same powder X-ray diffraction qualitative analysis, α-F
It was confirmed that the e 2 O 3 phase was also present. Also PV
A in a nitrogen atmosphere,
When kept at 100 ° C. for 10 hours, α-Fe 2
It was confirmed that the O 3 phase was also present. In any of these cases, no single-phase magnetite powder was obtained.
【００１７】[0017]
【発明の効果】本発明は上記のように、ヘマタイト粉に
有機物などを適量添加して不活性ガス中で加熱処理する
方法なので、容易に且つ安価に、高品質の単相マグネタ
イト粉を製造できる。また通常のフェライト生産設備を
利用でき、匣鉢に一度に多量のヘマタイト粉を入れて処
理できるため、極めて生産効率が良好となる。As described above, according to the present invention, a high-quality single-phase magnetite powder can be easily and inexpensively manufactured because a proper amount of an organic substance or the like is added to hematite powder and heat treatment is performed in an inert gas. . In addition, since ordinary ferrite production equipment can be used and a large amount of hematite powder can be put into the sagger at once and processed, the production efficiency becomes extremely good.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 下川 明 東京都港区新橋５丁目36番11号 富士電 気化学株式会社内 (56)参考文献 特開 昭55−104924（ＪＰ，Ａ) 特公 昭59−7646（ＪＰ，Ｂ２) 特公 昭53−24637（ＪＰ，Ｂ２) 米国特許2900236（ＵＳ，Ａ) ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akira Shimokawa 5-36-11 Shimbashi, Minato-ku, Tokyo Inside Fuji Electric Chemical Co., Ltd. (56) References JP-A-55-104924 (JP, A) Sho 59-7646 (JP, B2) Japanese Patent Publication Sho 53-24637 (JP, B2) US Patent 2,900,236 (US, A)
Claims (3)
又は二重結合を有する液状又は粉末状物質を０．１〜
４．０重量％加え、ほぼ均一に混合した後、不活性ガス
中で１２００〜１４５０℃で加熱処理することを特徴と
する単相マグネタイト粉の製造方法。1. A liquid or powdery substance having a single bond or a double bond between carbon atoms is added to a hematite powder in an amount of 0.1 to 0.1.
A method for producing a single-phase magnetite powder, comprising adding 4.0% by weight, mixing substantially uniformly, and heat-treating the mixture at 1200 to 1450 ° C in an inert gas.
する液状又は粉末状物質が有機結合剤である請求項１記
載の方法。2. The method according to claim 1, wherein the liquid or powdery substance having a single bond or a double bond between carbon atoms is an organic binder.
合剤を加え、造粒処理によりヘマタイト粉を球状顆粒と
し、生成するマグネタイト粉を球状とする請求項２記載
の方法。3. The method according to claim 2, wherein an organic binder is added before the heat treatment in an inert gas, and the hematite powder is formed into spherical granules by a granulation treatment, and the generated magnetite powder is formed into a spherical shape.
Priority Applications (11)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14147393A JP2614810B2 (en) | 1993-05-20 | 1993-05-20 | Method for producing single-phase magnetite powder |
| TW083102501A TW251373B (en) | 1993-05-20 | 1994-03-22 | |
| DE69403611T DE69403611T2 (en) | 1993-05-20 | 1994-03-31 | METHOD FOR PRODUCING HOMOGENIC MAGNETITE |
| AU62922/94A AU6292294A (en) | 1993-05-20 | 1994-03-31 | Process for manufacturing homogeneous magnetite |
| BR9405363-4A BR9405363A (en) | 1993-05-20 | 1994-03-31 | Process for producing a single-phase magnetite powder |
| PCT/JP1994/000531 WO1994027911A1 (en) | 1993-05-20 | 1994-03-31 | Process for manufacturing homogeneous magnetite |
| EP94910579A EP0653379B1 (en) | 1993-05-20 | 1994-03-31 | Process for manufacturing homogeneous magnetite |
| US08/313,152 US5512195A (en) | 1993-05-20 | 1994-03-31 | Process for producing single phase magnetite powder |
| KR1019940704668A KR100279651B1 (en) | 1993-05-20 | 1994-03-31 | Method for manufacturing single phase magnetite powder |
| CN94190295A CN1037836C (en) | 1993-05-20 | 1994-03-31 | Process for manufacturing homogeneous mgnetite |
| CA002133642A CA2133642C (en) | 1993-05-20 | 1994-03-31 | Process for producing single phase magnetite powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14147393A JP2614810B2 (en) | 1993-05-20 | 1993-05-20 | Method for producing single-phase magnetite powder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06329418A JPH06329418A (en) | 1994-11-29 |
| JP2614810B2 true JP2614810B2 (en) | 1997-05-28 |
Family
ID=15292708
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14147393A Expired - Fee Related JP2614810B2 (en) | 1993-05-20 | 1993-05-20 | Method for producing single-phase magnetite powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2614810B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2860356B2 (en) * | 1994-02-15 | 1999-02-24 | 富士電気化学株式会社 | Oxide magnetic material and method for producing the same |
| JP5307414B2 (en) * | 2008-02-07 | 2013-10-02 | Ｄｏｗａエレクトロニクス株式会社 | Magnetic carrier core material for electrophotographic developer, magnetic carrier for electrophotographic developer, and method for producing electrophotographic developer |
| JP5366069B2 (en) * | 2008-03-26 | 2013-12-11 | パウダーテック株式会社 | Ferrite particles and manufacturing method thereof |
-
1993
- 1993-05-20 JP JP14147393A patent/JP2614810B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06329418A (en) | 1994-11-29 |
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